Usman Khawaja one of world's best: Watson

Shane Watson has declared Sydney Thunder teammate Usman Khawaja one of the best batsman in the world and says he's been burdened by pressure and doubt throughout his national career.

Just as he did two years ago, Khawaja looks capable of single-handedly carrying the Thunder to the Big Bash League title.

After his game-winning 85 in Thursday night's win over reigning champions the Perth Scorchers, the classy left-hander is in devastating form.

Just as he did during the Thunder's title-winning season in 2015-16, Khawaja has returned from national duties in ominous touch.

He has hit 50s in each of his past five BBL innings, the first player to do so.

Thunder skipper and former Australian allrounder Watson said Khawaja was playing like a man unburdened by over-thinking or speculation about his future.

"I"m just thrilled for Uz, to see him play with that much freedom. It just shows he's one of the best batsmen in the world - not just in Australia," Watson said.

"To dismantle a high-quality bowling attack like he did (against the Scorchers) is incredible.

"From my perspective, it just comes down to the freedom he has when he plays for the Thunder and he's not getting extra scrutiny at that next level around whether he's going to play, whether he's in the team, whether he's not in the team.

"It's a different mentality and it's sad to see when the pressure can engulf someone that much.

"It does. It happened to me a lot."

Khawaja is in rare touch after hitting 171 in the final Ashes Test but was overlooked for the Australian ODI squad to take on England.

The Thunder go into Saturday's derby with the Sydney Sixers a win outside the top four, but Khawaja could be the ace up their sleeve in the back half of the season.

Watson said Khawaja was a different player when he pulled on a Thunder shirt.

"There's a calmness and confidence and it's very different," Watson said.

"There's no doubt. I know from my experience that when there's talk about people getting dropped or whether you're playing sub-continent or whether you're playing Australia, whatever it is, it puts more pressure on you knowing that if you make a mistake, your dream of playing for Australia is gone."